Bacterial adhesion
Although bacteria adhere to many different types of surfaces present in their habitat, this review focuses on bacterial adhesion to animal cells and tissues as a first step in the ability of pathogens to colonize and subsequently cause tissue damage. Accordingly, basic principles that govern the interaction of bacterial adhesins to their cognate receptors on animal cells are presented, such as fimbriae as adhesin structures. Significantly, we discuss the types of receptor-adhesin relationship, the phenomenon of multiple adhesins each specific for distinct receptors produced by pathogenic clones, the identity of glycoconjugates as receptors for lectins that serve as adhesins, and the interaction of bacterial adhesins with the extracellular matrix on animal tissues. Finally, a specific section is devoted to recent developments in preventing or treating infections by blocking bacterial adhesion to animal cells. In this context, a review of the different approaches of antiadhesion therapy is discussed, including the use of receptor and adhesin analogs, dietary constituents, sub-lethal concentrations of antibiotics, and adhesin-based vaccines. A discussion and summary of these topics focus on the in vivo data, including human trials, whereby plant extracts are used as a source of antiadhesion agents to prevent or treat urinary tract infections caused by Escherichia coli and infectious gastritis or peptic ulcer diseases induced by Helicobacter pylori and to maintain oral health.